Evidence of the eff ects of fi re on branching and leaf development in cerrado trees

Abstract

We discuss evidence of eff ects of an accidental fi re on shoot growth and leaf development in six cerrado tree species with distinct leaf phenologies. Buds of all six species were marked before shoot and leaf emergence in the dry season. After fi re, leaf and shoot growth were monitored weekly and specifi c leaf area (SLA) was determined. Shoot order was determined in the growing season. Evergreens and semideciduous woody species had rapid leaf and shoot growth and decreased leaf life span (LLS) after fi re compared with published data for evergreens in cerrado areas without fi re. On the other hand, Kielmeyera variabilis, a deciduous species, showed intense branching and produced two orders of shoots in one growing season. Fires promote rapid leaf and shoot growth in evergreens owing to reserve accumulations that allow survivorship after disturbances. However, the leaves produced by evergreens after fi re had high SLAs and were discarded before the next rainy season (short LLS). Th is leaf cohort was produced with less carbon per leaf, and the decreased LLS prevented herbivory and water loss during the dry season. Fire is an important factor of cerrado environments, infl uencing leaf production and shoot architecture in cerrado trees.